Epitaxial Growth of CdS Nanoparticle on Bi2S3 Nanowire and Photocatalytic Application of the Heterostructure

Bi2S3 nanowire/CdS nanoparticle heterostructure has been designed and constructed through an easy wet-chemistry approach at 140 degrees C for 8 h. The product is mainly composed of Bi2S3 nanowires, several hundred nanometers long and 10 nm wide, and epitaxially grown triangle-like CdS nanoparticles with size of 20 nm at their surfaces. A possible sequential deposition growth mechanism is proposed on the basis of experimental results to reveal the formation of the nanoscale heterostructure. Under the irradiation of UV light, the as-prepared nanoscale Bi2S3/CdS heterostructure exhibits enhanced photochemical efficiency that can be mainly attributed to the microstructure of the product. In the nanoscale heterostructure, the CdS nanoparticle not only determines the overall band gap energy, but also controls the charge carrier transition;recombination, and separation, while the Bi2S3 nanowire serves as support for the CdS nanoparticle, defines the specific surface area of the product and thus influences the photocatalytic activity. The effects of reaction parameters on the structure and photocatalytic activity of the final product are also discussed.